diff --git a/module/Core/src/Exception/NonUniqueSlugException.php b/module/Core/src/Exception/NonUniqueSlugException.php
index fb7e4503..9e22d354 100644
--- a/module/Core/src/Exception/NonUniqueSlugException.php
+++ b/module/Core/src/Exception/NonUniqueSlugException.php
@@ -4,10 +4,19 @@ declare(strict_types=1);
 
 namespace Shlinkio\Shlink\Core\Exception;
 
+use Fig\Http\Message\StatusCodeInterface;
+use Zend\ProblemDetails\Exception\CommonProblemDetailsExceptionTrait;
+use Zend\ProblemDetails\Exception\ProblemDetailsExceptionInterface;
+
 use function sprintf;
 
-class NonUniqueSlugException extends InvalidArgumentException
+class NonUniqueSlugException extends InvalidArgumentException implements ProblemDetailsExceptionInterface
 {
+    use CommonProblemDetailsExceptionTrait;
+
+    private const TITLE = 'Invalid custom slug';
+    public const TYPE = 'INVALID_SLUG';
+
     public static function fromSlug(string $slug, ?string $domain): self
     {
         $suffix = '';
@@ -15,6 +24,13 @@ class NonUniqueSlugException extends InvalidArgumentException
             $suffix = sprintf(' for domain "%s"', $domain);
         }
 
-        return new self(sprintf('Provided slug "%s" is not unique%s.', $slug, $suffix));
+        $e = new self(sprintf('Provided slug "%s" is already in use%s.', $slug, $suffix));
+
+        $e->detail = $e->getMessage();
+        $e->title = self::TITLE;
+        $e->type = self::TYPE;
+        $e->status = StatusCodeInterface::STATUS_BAD_REQUEST;
+
+        return $e;
     }
 }
diff --git a/module/Core/test/Exception/NonUniqueSlugExceptionTest.php b/module/Core/test/Exception/NonUniqueSlugExceptionTest.php
index 71c4a276..d2008621 100644
--- a/module/Core/test/Exception/NonUniqueSlugExceptionTest.php
+++ b/module/Core/test/Exception/NonUniqueSlugExceptionTest.php
@@ -22,12 +22,12 @@ class NonUniqueSlugExceptionTest extends TestCase
     public function provideMessages(): iterable
     {
         yield 'without domain' => [
-            'Provided slug "foo" is not unique.',
+            'Provided slug "foo" is already in use.',
             'foo',
             null,
         ];
         yield 'with domain' => [
-            'Provided slug "baz" is not unique for domain "bar".',
+            'Provided slug "baz" is already in use for domain "bar".',
             'baz',
             'bar',
         ];
diff --git a/module/Rest/src/Action/ShortUrl/AbstractCreateShortUrlAction.php b/module/Rest/src/Action/ShortUrl/AbstractCreateShortUrlAction.php
index d627b427..38daf905 100644
--- a/module/Rest/src/Action/ShortUrl/AbstractCreateShortUrlAction.php
+++ b/module/Rest/src/Action/ShortUrl/AbstractCreateShortUrlAction.php
@@ -7,7 +7,6 @@ namespace Shlinkio\Shlink\Rest\Action\ShortUrl;
 use Psr\Http\Message\ResponseInterface as Response;
 use Psr\Http\Message\ServerRequestInterface as Request;
 use Psr\Log\LoggerInterface;
-use Shlinkio\Shlink\Core\Exception\NonUniqueSlugException;
 use Shlinkio\Shlink\Core\Exception\ValidationException;
 use Shlinkio\Shlink\Core\Model\CreateShortUrlData;
 use Shlinkio\Shlink\Core\Service\UrlShortenerInterface;
@@ -16,8 +15,6 @@ use Shlinkio\Shlink\Rest\Action\AbstractRestAction;
 use Shlinkio\Shlink\Rest\Util\RestUtils;
 use Zend\Diactoros\Response\JsonResponse;
 
-use function sprintf;
-
 abstract class AbstractCreateShortUrlAction extends AbstractRestAction
 {
     /** @var UrlShortenerInterface */
@@ -52,21 +49,13 @@ abstract class AbstractCreateShortUrlAction extends AbstractRestAction
         }
 
         $longUrl = $shortUrlData->getLongUrl();
+        $tags = $shortUrlData->getTags();
         $shortUrlMeta = $shortUrlData->getMeta();
 
-        try {
-            $shortUrl = $this->urlShortener->urlToShortCode($longUrl, $shortUrlData->getTags(), $shortUrlMeta);
-            $transformer = new ShortUrlDataTransformer($this->domainConfig);
+        $shortUrl = $this->urlShortener->urlToShortCode($longUrl, $tags, $shortUrlMeta);
+        $transformer = new ShortUrlDataTransformer($this->domainConfig);
 
-            return new JsonResponse($transformer->transform($shortUrl));
-        } catch (NonUniqueSlugException $e) {
-            $customSlug = $shortUrlMeta->getCustomSlug();
-            $this->logger->warning('Provided non-unique slug. {e}', ['e' => $e]);
-            return new JsonResponse([
-                'error' => RestUtils::getRestErrorCodeFromException($e),
-                'message' => sprintf('Provided slug %s is already in use. Try with a different one.', $customSlug),
-            ], self::STATUS_BAD_REQUEST);
-        }
+        return new JsonResponse($transformer->transform($shortUrl));
     }
 
     /**
diff --git a/module/Rest/src/Util/RestUtils.php b/module/Rest/src/Util/RestUtils.php
index 279d7fca..24398eb9 100644
--- a/module/Rest/src/Util/RestUtils.php
+++ b/module/Rest/src/Util/RestUtils.php
@@ -19,7 +19,8 @@ class RestUtils
     /** @deprecated */
     public const INVALID_URL_ERROR = Core\InvalidUrlException::TYPE;
     public const INVALID_ARGUMENT_ERROR = 'INVALID_ARGUMENT';
-    public const INVALID_SLUG_ERROR = 'INVALID_SLUG';
+    /** @deprecated */
+    public const INVALID_SLUG_ERROR = Core\NonUniqueSlugException::TYPE;
     public const INVALID_CREDENTIALS_ERROR = 'INVALID_CREDENTIALS';
     public const INVALID_AUTH_TOKEN_ERROR = 'INVALID_AUTH_TOKEN';
     public const INVALID_AUTHORIZATION_ERROR = 'INVALID_AUTHORIZATION';
diff --git a/module/Rest/test/Action/ShortUrl/CreateShortUrlActionTest.php b/module/Rest/test/Action/ShortUrl/CreateShortUrlActionTest.php
index 1cc5c889..c4f8970d 100644
--- a/module/Rest/test/Action/ShortUrl/CreateShortUrlActionTest.php
+++ b/module/Rest/test/Action/ShortUrl/CreateShortUrlActionTest.php
@@ -8,8 +8,6 @@ use PHPUnit\Framework\TestCase;
 use Prophecy\Argument;
 use Prophecy\Prophecy\ObjectProphecy;
 use Shlinkio\Shlink\Core\Entity\ShortUrl;
-use Shlinkio\Shlink\Core\Exception\NonUniqueSlugException;
-use Shlinkio\Shlink\Core\Model\ShortUrlMeta;
 use Shlinkio\Shlink\Core\Service\UrlShortener;
 use Shlinkio\Shlink\Rest\Action\ShortUrl\CreateShortUrlAction;
 use Shlinkio\Shlink\Rest\Util\RestUtils;
@@ -88,23 +86,4 @@ class CreateShortUrlActionTest extends TestCase
         yield ['127.0.0.1'];
         yield ['???/&%$&'];
     }
-
-    /** @test */
-    public function nonUniqueSlugReturnsError(): void
-    {
-        $this->urlShortener->urlToShortCode(
-            Argument::type(Uri::class),
-            Argument::type('array'),
-            ShortUrlMeta::createFromRawData(['customSlug' => 'foo']),
-            Argument::cetera()
-        )->willThrow(NonUniqueSlugException::class)->shouldBeCalledOnce();
-
-        $request = (new ServerRequest())->withParsedBody([
-            'longUrl' => 'http://www.domain.com/foo/bar',
-            'customSlug' => 'foo',
-        ]);
-        $response = $this->action->handle($request);
-        $this->assertEquals(400, $response->getStatusCode());
-        $this->assertStringContainsString(RestUtils::INVALID_SLUG_ERROR, (string) $response->getBody());
-    }
 }